CROWN DRILLING BIT Russian patent published in 2006 - IPC E21B10/26 E21B10/36 

FIELD: drilling equipment, particularly rock-cutting tools for rotary-percussion drilling of hard rock.

SUBSTANCE: crown drilling bit comprises advance rock cutting head and shank adapted to receive removable ring reinforced with hard-alloy inserts. The advance rock cutting head may be axially displaced relatively removable ring and is connected to the shank by means of spline connection. Ball body is located under head end in shank cavity. Resilient ring cooperating with removable ring is installed on the spline connection.

EFFECT: increased drilling rate.

3 dwg